+bonifartius 𒂼𒄄
maybe someone can enlighten me:
why is/was hydrogen as energy storage torpedoed for decades now (that it is too late)? it's clean after burning it, can be produced from either electrolysis or natural gas. storage is a bit complicated, but manageable. why should this be worse than batteries?
i've read so many shitty reasons why H2 is "bad":
- "converting natural gas isn't green": yes no shit, but it helps to fill the gap. should've started earlier.
- "not enough power to do electrolysis": every other energy storage solution seems worse at large scales, especially batteries.
- "not enough platinum to use as catalyst for fuel-cells": i bet you can throw enough research on it and find another catalyst. hell, _we_ are full of catalysts that don't contain platinum.
@bonifartius H2 gas has a reasonable energy density in J/kg, but since it has such a low density in kg/m³, it has a poor volumetric energy density in J/m³.
Another way to look at this is to say H2's enthalpy of combustion in kg/mol is very low (propane's is about eight times higher), so you need far more moles of hydrogen to store equal amounts of energy. But here you run into the ideal gas law P=ρRT. To get many moles into a reasonable amount of space, we need a high density ρ. R is a physical constant, and so you either need to drop T by refrigerating your storage, or raise P by physically reinforcing it. Both of those options are too heavy to be competitive for mobile applications - even if you don't have to carry around as many kg of fuel, you're losing more than the difference in carrying around the tank to hold it in. For static applications where you can tolerate the weight, there are other cheaper ways (notably, pumped-storage hydro) to store your energy.
@khird
i can see that the density isn't ideal which makes the processing into methane etc. interesting. i can't find the paper on that now, but i swear the stuff i read about wasn't very complicated.
the problem with things like pumped storage is that they need the right geology for that. e.g. in northern germany there aren't that many places which are hilly and not populated.
my point is: _if_ we put wind and solar everywhere it's dumb to turn of those things because there is "too much power" (which happens frequently). would make more sense to just run electrolysis with it, maybe convert that H2 into methane or whatever. i don't see that big batteries are a good solution for this, even if all the car manufacturers want us to believe that using old car batteries for storage is a great solution ;)
not poer storage: what makes H2 interesting too is that it can be used for other things like haber-bosch.